Diabetes is the seventh leading cause of death in the United States. Almost 20 million Americans now have diabetes and the incidence rate is increasing. Experts predict t0% of the US population will be diabetic by the end of decade. Type 2 diabetes (T2D) currently costs the US $100 billion per year. Associated with the nation's spiraling obesity rates, increasing numbers of children, primarily of African- American and Hispanic ethnicity, are being diagnosed with T2D. Recent results from the multiyear Diabetes Prevention Program trial provide strong evidence that diabetes can be prevented through lifestyle modifications. Behavioral intervention programs can effect positive and lasting lifestyle change. The most successful use focused, highly tailored messages and one-on-one counseling. Unfortunately, one-on-one strategies are intrinsically costly and inefficient to apply to large groups. Population-based T2D behavior change programs using traditional print, radio and television have proven only marginally effective. Computers offer an opportunity to highly tailor behavior change messages to culture and individual. The flexibility and cost effectiveness of digital media also makes it attractive for reaching large numbers of at-risk individuals. Middle schools' established setting for delivering behavior change messages (smoking, drugs, AIDS, etc.) and high penetration rate of computers makes them ideally suited to computer-based interventions. We believe a national market exists for a school-oriented, computer-based intervention (CBI) product that promotes healthy nutrition and physical activity. The objective of this SBIR grant proposal is the development and testing of that product. Our long-term goal is reducing the incidence of T2D and related health problems. Our central hypothesis is that interactive media tailored to individual psychosocial and environmental characteristics will reduce T2D risks. This research will deliver, for the first time, populationbased, individually tailored, behavioral change messages to prevent T2D. This Phase I application encompasses the formative assessment and development of the 7thgrade CBI, with a prototype for session I that is alpha and beta tested as the deliverable.